Summary

Genetic factors appear to contribute to the severity and progression
of diabetic retinopathy.We assessed the associations
of the C807T and Glu505Lys variants of the glycoprotein Ia
(2 integrin) subunit of the platelet/endothelial collagen receptor
and risk of retinopathy in a population-based survey of
288 diabetic patients in one Swedish community. Neither
variant was associated with retinopathy risk overall. However,
the 807T variant was associated with increased risk of severe
retinopathy, and the association was modified by diabetes
duration. Among patients with diabetes of longer duration
(25 years), the 807T variant was strongly associated with risk
of severe retinopathy (odds ratio 7.49, 95% confidence interval1.75 to 32.1). There was no association between the 807T
variant and risk of severe retinopathy among patients with diabetes
duration <25 years. The Lys505 variant of glycoprotein Ia
was associated with an odds ratio for severe retinopathy of
1.88 (95% confidence interval 0.83 to 4.24). Overall, there was
a significant interaction between glycoprotein Ia genotype and
duration of diabetes on the risk of retinopathy (P-value for
interaction = 0.019).These results suggest the hypothesis that
genetic variation of platelet glycoprotein Ia may play a particularly
important role during the advanced stages of diabetic
retinopathy.